Communication device for a landborne vehicle

ABSTRACT

A communications system for land vehicles usable in the field of radio communications with any electronic data processing equipment connected to a mobile telecommunications network. The communications system enables the connection of a communication terminal (TP_i) to a mobile communications network ( 2 ) from a vehicle ( 1 ) of the kind including a local network (PAN) linked to the vehicle, and a server for connecting said local network to the communications network (GPRS, UMTS). The local network ( 3 ) provides a resource (Cext) for connecting a requesting communications terminal (TP_k) and the mobile communications network ( 2 ), and resources (Cint) for setting up a connection between two mobile terminals (TP_i, TP_j) connected to the local network (PAN) linked to the vehicle.

The present invention relates to a communications system for a land vehicle. It finds an application in the field of radio communications and makes it possible to use multimedia services normally accessible by any electronic data processing equipment connected to a mobile telecommunications network, while on board a land vehicle such as a motor vehicle.

In the context of the invention, a plurality of persons in a vehicle can access various communications services via the Internet. These users in the vehicle use their personal electronic data processing terminals to access multimedia services. In a first embodiment, the access mode is GPRS telephony mode. In a second embodiment, the access mode is UMTS telephony mode.

In the context of the invention, an electronic data processing terminal is connected to the mobile network via a personal wireless network using the Bluetooth™ or WiFi™ protocol, for example. The application field is therefore that of data and the access mode is the packet mode. However, this invention is not limited to data services, because the system for connecting the local network to the mobile network can also provide a telephone service, provided that the service is based on the Voice over IP (VoIP) technique.

In the context of the invention, two techniques co-operate to achieve these objectives:

-   -   firstly, the access network (GPRS, UMTS), which operates in         packet mode,     -   secondly, the short-range communications technology, such as the         Bluetooth™ technology, so that it is possible to interconnect a         plurality of terminals and more particularly at most N−1         terminals connected to an N^(th) terminal that serves as the         system for connecting a local network of N local stations to the         mobile network.

The use of a piconet local network, such as a Bluetooth™ technology local network, associated with an access point to a network, whether fixed or mobile, is described in a number of prior art publications and has led to industrial implementation.

Access point products enabling access by electronic data processing terminals equipped with a Bluetooth™ interface to the high bit rate ADSL fixed network may be mentioned.

Systems for connecting a Bluetooth™ “piconet” local network to a mobile network via a mobile telephone may also be mentioned. A mobile telephone then serves as a gateway between the mobile network and the Bluetooth™ piconet local network.

The company IXI Mobile Inc. of Palo Alto, Calif. has more particularly developed a Personal Mobile Gateway (PMG) system enabling connection to a GPRS network of a plurality of electronic data processing terminals equipped with Bluetooth™ short-range communications interfaces. The architecture of that system is based on a small system (known as the PMG) which provides functions for connecting to the network via a GPRS radio module. That system is also equipped with a Bluetooth™ radio module. In addition to the functions mentioned above, the PMG also provides microrouter and microserver functions for GPRS radio connectivity and Bluetooth™ radio connectivity. In particular, the microserver provides functions for setting parameters of the piconetwork formed in this way by the various personal electronic data processing devices. These parameter setting functions concern in particular the devices that may be connected and the applications using the capacities of the system. The concept developed by IXI is therefore the opposite of the “all in one” terminal concept based on the possibility of a single terminal providing all the services that a mobile user requires.

There is also described in the prior art the implementation in a motor vehicle of a system offering services available via a UMTS mobile network. The bit rate available on the mobile connection is 128 kilobits per second (kbit/s) and the services that have been demonstrated include direct video, downloading of music tracks, videophony, and an offboard navigation system. The communications services offered may include those of the professional (business services), mobility, entertainment, and information fields. All of those services benefit from video support. In that experimental version, the vehicle is equipped with IBM-PC computers and display screens disposed in the seatbacks. Those devices are not interconnected by a short-range radio connection, for example of the Bluetooth™ type, but instead by a cable harness.

European Patent application EP-A2-1.209.928 discloses a system whose architecture is based on a server (preferably of the PC type). That server is installed in a vehicle, preferably a rail car, and is equipped with two types of radio interface, the first of which is preferably of the W-CDMA (UMTS) type, in order to access remote servers, while the second is a short-range radio interface (preferably of the Bluetooth™ type). The system is completed by a service controller server responsible for controlling access to the resources of the first server. The system described is for public use and the terminals with access to the first server or to the remote servers, which are preferably mobile telephones, belong to members of the general public.

Also, the above system is not based on the use of multimedia services available to a personal network via a packet mode mobile network (such as a GPRS network); to the contrary, such access is made available to the “general public”. To this end, upon activation of each session, the terminal in use must in particular use an “access controller” system to carry out a security procedure including an identification step followed by an authentication step.

An analysis of the prior art indicates the following problems:

-   -   The association of a set of personal electronic data processing         devices forming a personal network and a mode of access to a         packet (GPRS) mobile network is described but there is no         disclosure as to any form of use in the motor vehicle field. The         access point to the mobile telephone network is itself a         portable element and the prior art proposes that it be         integrated into a mobile telephone.     -   The application to data services provided in a vehicle offers         services accessed via the UMTS network. The terminals on which         the services are available are integrated into the vehicle and         the local network is a static network.     -   The interaction between means giving radio access to the mobile         network and a wireless local network is already known in the         art. However, there is no personal network concept in the prior         art, since the local network is inherently open to the general         public. It is therefore necessary to carry out the various         procedures for accessing this local network, which then provides         access to the W-CDMA mobile network.

The present invention provides a remedy to the above problems of the prior art. It relates to a communications system for enabling connection of a communications terminal to a mobile communications network from a vehicle of the kind including a GPRS or UMTS type communications network connection server. According to the invention the system comprises:

-   -   a PAN local network linked to the vehicle and consisting of a         mobile terminal that is not necessarily attached to said vehicle         and is provided with wireless connection means such as an IrDa         infrared interface or a Bluetooth™ radio interface;     -   means for providing a resource for connecting a requesting         communications terminal to the mobile communications network;         and     -   means for providing a resource for interconnecting two mobile         terminals connected to the local network linked to the vehicle.

Said local network includes means for providing a resource for connecting a requesting communications terminal and the mobile communications network and the communications server includes resources for setting up a connection (Cint) between two mobile terminals (TP_i, TP_j) connected to the local network (PAN) linked to the vehicle and a connection (Cext) to the mobile communications network (GPRS).

Other features and advantages of the present invention are explained with the aid of the following description and the appended drawings, in which:

FIG. 1 is a block diagram of a system of the invention;

FIG. 2 is a block diagram of one particular embodiment of a system of the invention;

FIG. 3 is a block diagram of one particular embodiment of a system of the invention;

FIG. 4 is a block diagram of one particular embodiment of a system of the invention.

A first feature of the system of the invention is the use of a personal wireless network (preferably of the Bluetooth™ type) in a motor vehicle, this personal network consisting of various electronic data processing or telecommunications terminals such as a personal computer (PC), personal digital assistant (PDA), MP3 music player, mobile telephone, tablet computer, etc.

These electronic data processing terminals are preferably portable, i.e. are not attached in any manner whatsoever to the motor vehicle. They are connected to a personal area network (PAN) via a contactless communications interface, preferably of the Bluetooth™ type.

However, the system of the invention is not limited to portable terminals. It may include service access terminals integrated into the vehicle, whether they are connected to the PAN by Bluetooth™ wireless connection means (which is preferable) or by cables, as explained below in the description.

A second feature of the system of the invention is the connection of the PAN to a mobile telephone network (for example of the GPRS or UMTS type). This connection is provided by a radio module providing an interface to the mobile network. In the remainder of the document the common point between the mobile network and the PAN is referred to as the system for connecting the local network to the mobile network. This system for connecting the local network to the mobile network provides routing functions enabling connection of any terminal belonging to the PAN to an application server accessed via the mobile network.

The invention therefore offers a system capable of simultaneously connecting at most a particular number of terminals, such as a group of at most seven terminals in a Bluetooth™ piconet, whilst delivering multimedia services to application servers that are accessed via the mobile network. The applications accessed are not mutually dependent in any way. Also, for example, the terminals access services having data content, such as text, graphic, sound or video data, and/or electronic data processing program content, such as an ASP application, a forms service, etc.

According to one essential aspect of the invention, access to different contents is effected simultaneously by the system for connecting the local network to the mobile network. Mention can be made of access to the worldwide web (WWW), service portals such as an Orange portal, entertainment services, traffic information services, videophone services. This list is given by way of example and is in no way limiting on the invention.

A third feature of the system of the invention is that it includes means whereby two electronic data processing terminals are able to communicate with each other using the resources of the system for connecting the local network to the mobile network. In this case, the system includes means for providing routing functions within the PAN without accessing the mobile communications network.

FIG. 1 shows one embodiment of a system of the invention implemented in a vehicle 1.

The vehicle 1 may consist of a motor vehicle, a rail car, the passenger compartment of a bus or a coach, or a mobile home.

The mobile communications network 2 may be a GPRS or UMTS network. It may be used to access electronic data processing resources or information or data contents.

Inside the vehicle 1, there is a local network 3 that is provided with means for connecting it to the mobile communications networks 2 and with means for its wireless connection to a plurality of terminals TP_i, TP_j, TP_k.

The system of the invention includes control means for the local network 3, consisting of:

-   -   means for connecting a terminal TP_k to the mobile         communications network 2 via an external communications resource         Cext;     -   means for connecting two or more terminals TP_i and TP_k to each         other via the local network 3 without having to connect to the         mobile communications network 2.

In one particular embodiment, the invention is based on the association of three elements.

The first element consists of the personal area network (PAN) as such. In one particular embodiment, the PAN uses means defined in the Bluetooth™ technology. The profile used is the PAN profile defined by the Bluetooth™ SIG (which is the organization that produces the Bluetooth™ specifications) and is managed on the system of the invention by PAN profile management means. The various electronic data processing terminals have the PAN User (PANU) function and the system for connecting the local network to the mobile network has the network access point (NAP) function. The network access point, which here is implemented in the system for connecting the local network to the mobile network, must be set to multi-user mode. In this case, the network access point cooperates with means for configuring it as the Bluetooth™ piconet master and the various terminals TP_i as piconet slaves.

In one particular embodiment, the system for connecting the local network to the mobile network is constructed on an Ipaq™ (Hewlett-Packard personal digital assistant (PDA)) platform. The operating system is the “Familiar” version of Linux.

In one particular embodiment, in order to offer an economical solution, the system for connecting the local network to the mobile network is implemented in an electronic component (integrated circuit, such as a PLD integrated circuit).

The second element of the invention uses the communications interface to the mobile (preferably GPRS) network. It comprises a hardware portion and a software portion.

The hardware portion, shown diagrammatically in FIG. 2, in which elements that are common to FIG. 1 are not described further, is implemented by means for implementing a communications interface to the mobile telephone network.

In one embodiment, the means for implementing a communications interface to the mobile telephone network include three elements:

-   -   the system 5 for connecting the local network to the mobile         network, already defined,     -   a WIreless Standard MOdule (WISMO) type GSM/GPRS modem 7 which         cooperates with means for producing and executing a standard AT         Commands protocol and conforms to the specifications of the ETSI         GSM 07/07 standard; in one particular embodiment, the modem         cooperates with SIM card management means 6′,8,     -   a handsfree system 6 for connection to the GSM network, adapted         to be installed in the vehicle. In the case of a motor vehicle,         this handsfree system for connection to the GSM network is an         appropriate unit available off the shelf, such as the CK 4000         from Parrot. This third element 6 is disposed between the system         5 for connecting the local network to the mobile network and the         modem 7, as shown in FIG. 2.

In one particular embodiment, the SIM card management means are not physically connected to the WISMO modem and the SIM cards are electrically emulated by electrical connections provided by the third element of the invention. The SIM card is present in a mobile telephone connected to the third element of the invention via the Bluetooth™ link. This enables the exchange between the WISMO type modem and the SIM card of the mobile telephone of messages conforming to the ETSI/GSM 07/11 specifications. Note that this embodiment is not specific to the invention, because the function implementing the system for connecting the local network to the mobile network is in no way dependent on the SIM card access mode. In a different embodiment, the modem 6 has a SIM card physically inserted into an appropriate connector (not shown) connected to the modem by an electronic circuit.

The software portion is implemented in the form of programs executed mainly by the system for connecting the local network to the mobile network. It is organized around the following functions:

1. The system 5 for connecting the local network to the mobile network executes the essential function of the invention. At the functional level, the system 5 for connecting the local network to the mobile network includes means for executing the following functions:

-   -   PAN local network constitution;     -   routing messages between each terminal and the application         server accessed by said terminal via the mobile network;     -   GPRS connection;     -   inter-PAN routing, i.e. routing between two service access         terminals (with no connection to the GPRS connection).

To provide the above four functions, the system 5 for connecting the local network to the mobile network includes software means for implementing the following functions:

-   -   IP Network Address Translation (NAT); this function translates         IP address assigned to the system for connecting the local         network to the mobile network on the PAN side and the IP address         assigned by the mobile network upon activation of the PDP         context (PDP ADDRESS); accordingly, the system 5 for connecting         the local network to the mobile network has two IP addresses,         one of which is assigned by the GPRS network and the second of         which is assigned statically or dynamically when the PAN is put         together; accordingly, the only address visible from the outside         (for example to application servers) is the first address (PDP         ADDRESS);     -   IP routing; this function routes IP packets to their destination         addresses;     -   Ethernet bridge; this function provides a bridge between the         various terminals constituting the PAN, the medium access         control (MAC) address used being the Bluetooth™ address; this         address is contained in the header of messages of the Bluetooth™         Network Encapsulation Protocol (BNEP) layer;     -   firewall for protecting the PAN from external attack;     -   activation of the connection to the GPRS network; this function         activates and deactivates the connection to the GPRS network and         consists of a set of AT commands that are sent to the GSM GPRS         modem; in addition to activation/deactivation of the connection         to the network, these commands are used to configure various         parameters of that connection; activation of a GPRS connection,         which is under the control of the system 5 for connecting the         local network to the mobile network, is triggered in three         modes:     -   automatically by one of the electronic data processing terminals         belonging to the PAN upon accessing a remote service;     -   at the request of one of the access terminals;     -   upon initializing the system for connecting the local network to         the mobile network, in which case the objective is to maintain         the connection active until it is stopped or reinitialized;     -   dynamic Internet connection IP address assignment; this function         for assigning IP addresses within the network PAN may be         executed dynamically by a Dynamic Host Configuration Protocol         (DHCP) server hosted by the system for connecting the local         network to the mobile network;     -   static Internet connection IP address assignment; this function         for assigning IP addresses within the network PAN may be         executed statically by a command line entered manually at a user         interface console which, depending on the embodiment, may be         managed by a portable terminal TP_i, the system for connecting         the local network to the mobile network, or the system 6 for the         connection to the GSM network.

The first solution constitutes a preferred embodiment in that it involves no user action. Within the PAN, each terminal has an IP address, including the system for connecting the local network to the mobile network. That address is attached to the interface pan0, as described below.

In the case of the present invention, the operating system of the system 5 for connecting the local network to the mobile network is Linux. The implementation of the functions of the system for connecting the local network to the mobile network is described below with reference to FIG. 3.

The system 5 for connecting the local network to the mobile network has a PAN demon (PANd) 9 whose function is to create a virtual network interface 11 for Ethernet communications with a client CL 0 to CL i.

Each client CL i is associated with a virtual interface bnepx. Once the Ethernet PAN has been set up, calls can be routed at the Ethernet level or at the IP level if an IP interface is associated with each virtual Ethernet interface.

Ethernet routing is effected by an Ethernet bridge 11 which in one embodiment is a 802.1d Ethernet bridge included in the Linux 2.4.x kernel.

The Ethernet bridge 11 is initialized on the system 5 for connecting the local network to the mobile network serving as a network access point NAP. It creates a new virtual interface pan0 combining the interfaces bnepx created for each connected client.

Once this operation has been effected, clients can be addressed directly by the MAC address of the Bluetooth™ peripherals and the system 5 for connecting the local network to the mobile network can be addressed by the MAC address of its Bluetooth™ peripheral.

In the context of IP routing, an IP address is associated with each virtual Ethernet interface. This address is assigned either by an automatic mechanism, such as a DHCP mechanism, or statically. When the IP addresses have been assigned, the system 5 for connecting the local network to the mobile network becomes the gateway of the PAN, which enables it to route IP packets to the required destination (inside or external to the PAN).

To connect the clients to an external network, the system 5 for connecting the local network to the mobile network sets up a new ppp0/GPRS communications interface. It then uses IP NAT address translation and firewall functions in the Linux 2.4.x kernel that enable it to show only a single entity on the external network (which may be a GPRS network, for example) and to protect the clients.

In FIG. 3, CL i are service access terminals, bnep0 is the virtual network interface to the service access terminals and to the system for connecting the local network to the mobile network to form the access point PAN, pan0 is the network interface of the system for connecting the local network to the mobile network on the PAN side, and ppp0/GPRS is the network interface of the system for connecting the local network to the mobile network on the GPRS side.

In the embodiment shown in FIG. 2, the service access terminals are connected via a Bluetooth™ short-range radio connection. A WiFi connection may be used subject to modifications that the person skilled in the art will know how to effect given the present description.

This corresponds to the situation in which the terminals TP_i are portable, each user having a portable terminal.

Other types of terminals may be connected to the network in another embodiment, shown in FIG. 4, in which components that also appear in FIG. 2 carry the same reference numbers and are not described further; these terminals are physically attached to the vehicle 1.

For example, a navigation system 20 is physically integrated into the dashboard of the motor vehicle 1. As a terminal of the local network 3, the navigation system 20 is connected in two ways to the system for connecting the local network to the mobile network:

-   -   by a Bluetooth™ radio interface (as in the case of portable         terminals),     -   by a cable connection. In this case, the system 5 for connecting         the local network to the mobile network (not shown in FIG. 4)         must provide a cable connection to the terminal 20, either a         direct connection, preferably of the serial type, or a         connection 21 via the third element (GSM/GPRS network connection         system 6). In which case, the connection can then use other         types of link, such as a Controller Area Network™ (CAN) bus.         This cable connection solution is not described further in the         context of the present embodiment.

2. The WISMO modem 7 can be any communications modem of this type available off the shelf. It requires no particular updating of its software version to provide the necessary communications functions associated with the implementation of the invention.

3. The GSM/GPRS network connection system 6 provides the connection between the modem 7 and the system 5 for connecting the local network to the mobile network, and is therefore transparent, merely transporting data between these two elements. This function is necessary when the system of the invention is implemented in the form of three separate elements.

This implementation of the functions in three separate elements (the system for connecting the local network to the mobile network, the modem, and the GSM/GPRS network connection system 6) must not be seen as obligatory. Only the functions executed therein that are described above are obligatory. The functions of the system for connecting the local network to the mobile network implemented by the first element (Ipaq) could be implemented in the GSM network connection system 6.

This second embodiment, shown in FIG. 4, therefore has an architecture based on two elements: the GSM network connection system 6, which provides the functions of the system for connecting the local network to the mobile network, and the GSM/GPRS modem, which provides the radio interface with the mobile network.

In this embodiment, there is a cable connection by means of a port to the CAN™ bus between an equipment integrated into the vehicle, which here is a navigation system, and the system for connecting the local network to the mobile network. 

1. A communications system for enabling connection of a communications terminal (TP_i) to a mobile communications network (2) from a vehicle (1) of the kind including a server for connecting to said mobile communications network 2, wherein the communications system comprises: a PAN local network (3) linked to the vehicle and consisting of a mobile terminal (TP_i) of said vehicle (1) and provided with wireless connection means; means for providing a resource (Cext) for connecting a requesting communications terminal (Tp_k) to said mobile communications network (2); means for providing a resource (Cint) for interconnecting two mobile terminals (Tp_i, Tp_j) connected to said PAN local network linked to the vehicle without accessing said mobile communications network (2); and said connection server being configured to establish at least one connection (Cint) and at least one connection (Cext) simultaneously.
 2. The system according to claim 1, wherein the PAN local network is connected to a mobile telephone network by a radio module providing the interface with the mobile network.
 3. The system according to claim 2, wherein the common point between the mobile network and the PAN local network includes a system (5) for connecting the local network to the mobile network which provides routing functions, enabling the connection of any terminal of the PAN local network to an application server accessed via the mobile network.
 4. The system according to claim 3, wherein different contents are accessed simultaneously by the system (5) for connecting the local network to the mobile network.
 5. The system according to claim 4, wherein the means for enabling communication between two electronic data processing terminals (TP_i, TP_j) use the resources of the system (5) for connecting the local network to the mobile network, which includes means for providing the routing functions within the PAN local network without accessing the mobile communications network.
 6. The system according to claim 1, further comprising: a personal access network (PAN); and a communications interface to the network.
 7. The system according to claim 6, wherein the personal access network (PAN) uses means defined in the Bluetooth™ technology and includes in particular PAN profile management means, a network access point NAP set to multi-user mode, and means for configuring it as a Bluetooth™ piconet master and the various terminals TP_i as piconet slaves.
 8. The system according to claim 6, further comprising a system (5) for connecting the local network to the mobile network constructed on a platform executing a Linux type operating system.
 9. The system according to claim 6, further comprising a system (5) for connecting the local network to the mobile network implemented in an electronic component.
 10. The system according to claim 6, wherein the communications interface to the network includes a hardware portion including, separately or in combination: a system (5) for connecting the local network to the mobile network, a WISMO (WIreless Standard MOdule) type modem (7), and a handsfree mobile network connection system (6) adapted to be mounted in the vehicle (1) and disposed between the modem (7) and the system (5) for connecting the local network to the mobile network.
 11. The system according to claim 10, wherein the modem (7) cooperates with means for producing and executing a standard AT Commands protocol.
 12. The system according to claim 10, wherein the modem (7) cooperates with SIM card management means (6′, 8).
 13. The system according to claim 12, wherein the SIM card management means (6′, 8) include means for emulating SIM cards by electrical connections to the mobile network connection system (6) and a SIM card in a mobile telephone (TP_k) connected to the GSM/GPRS network connection system (6) via the Bluetooth™ connection enables exchange between the modem (7) and the SIM card of the mobile telephone (TP_k) of messages.
 14. The system according to claim 12, wherein the SIM card management means (6′, 8) co-operate with the modem (7), which includes SIM card management means, a SIM card therein being physically inserted into the appropriate connector.
 15. The system according to claim 6, wherein the communications interface to the network includes a software portion implemented in the form of programs executed at the level of the system for connecting the local network to the mobile network.
 16. The system according to claim 15, wherein the system (5) for connecting the local network to the mobile network includes means for executing the following functions: personal network constitution; routing messages between each terminal and the application server accessed by said terminal via the mobile network; a GSM/GPRS connection; and inter-PAN routing, i.e. routing between two server access terminals (with no connection to the GSM/GPRS connection).
 17. The system according to claim 16, wherein the system (5) for connecting the local network to the mobile network (2) includes software means for providing one or more of the following functions: IP NAT (network address translation); IP routing, for routing IP packets to their destination addresses; an Ethernet bridge between the terminals constituting the PAN; a firewall for protecting the network PAN from external attack; activation and deactivation of the mobile network connection; dynamically assigning Internet connection IP addresses; assigning IP addresses within the PAN may be effected dynamically by a Dynamic Host Configuration Protocol (DHCP) server hosted by the system for connecting the local network to the mobile network; and statically assigning Internet connection IP addresses; assigning IP addresses within the PAN may be effected statically by a command line entered manually at a user interface console which, depending on the embodiment, may be managed by a portable terminal TP_i, the system (5) for connecting the local network to the mobile network or the mobile network connection system (6).
 18. The system according to claim 17, wherein the IP address translation function translates the IP address assigned to the system (5) for connecting the local network to the mobile network on the PAN side and the IP address assigned by the mobile network on activation of the PDP context (PDP ADDRESS), so that the system (5) for connecting the local network to the mobile network has two IP addresses, one assigned by the GSM/GPRS network and the second assigned statically or dynamically upon constitution of the PAN local network, the only address visible from the outside (for example to application servers) being the first address (PDP ADDRESS).
 19. The system according to claim 17, wherein the Ethernet bridge function uses a Medium Access Control (MAC) address based on the Bluetooth™ address contained in the header of the messages of the Bluetooth™ Network Encapsulation Protocol (BNEP) layer.
 20. The system according to claim 17, wherein the function for activating and deactivating the GSM/GPRS network connection includes a processor of AT commands that are sent to the GSM/GPRS modem and are used to configure parameters of this connection.
 21. The system according to claim 20, wherein the function for activating and deactivating the GSM/GPRS network connection, which is under the control of the system (5) for connecting the local network to the mobile network, is triggered in three different modes: automatically by one of the terminals upon access to a remote service; at the request of one of the access terminals; upon initialization of the system for connecting the local network to the mobile network, to maintain the connection active until it is stopped or reinitialized.
 22. The system according to claim 17, wherein the dynamic Internet connection IP address assignment function is provided by a DHCP server hosted by the system for connecting the local network to the mobile network.
 23. The system according to claim 17, wherein the static Internet connection IP address assignment function is executed by a command line entered manually at a user interface console which, depending on the embodiment, may be managed by a portable terminal (TP_i), the system (5) for connecting the local network to the mobile network or the GSM/GPRS network connection system (6).
 24. The system according to claim 16, wherein the system (5) for connecting the local network to the mobile network has a PAN demon (PANd) (9) for creating a virtual Ethernet network interface (11) for communication with a client (CL 0 to CL 1).
 25. The system according to claim 24, wherein Ethernet routing is effected by an Ethernet bridge (11) such as an 802.1d Ethernet bridge included in the Linux 2.4.x kernel, initialized on the system (5) for connecting the local network to the mobile network that serves as a network access point NAP for creating a new virtual interface pan0 combining the interfaces bnepX created for each connected client.
 26. The system according to claim 24, wherein the IP routing function associates with each virtual Ethernet interface an IP address assigned either by an automatic mechanism, such as a DHCP mechanism, or statically, so that, once the IP addresses have been assigned, the system (5) for connecting the local network to the mobile network becomes the gateway of the PAN, which enables it to route IP packets to the required destination within the PAN or externally.
 27. The system according to claim 26, wherein in order to connect clients to an external network, the system (5) for connecting the local network to the mobile network establishes a new ppp0/GPRS communications interface so as to show only a single entity on the external network and to protect clients.
 28. system according to, claim 1, wherein the personal network (3) includes terminals physically attached to the vehicle (1), such as a navigation system (20) connected to the system for connecting the local network to the mobile network by: a Bluetooth™ radio interface or an IrDa infrared interface (as in the case of portable terminals), or a cable connection.
 29. The system according to claim 28, wherein the system (5) for connecting the local network to the mobile network cooperates with a cable connection to the navigation system (20) either via a direct connection that is a serial connection or via a connection (21) via the GSM/GPRS network connection system (6).
 30. The system according to claim 29, wherein the connection is effected via the Controller Area Network™ (CAN) bus.
 31. The system according to claim 10, wherein the GSM/GPRS network connection system (6) for providing the connection between the modem (7) and the system (5) for connecting the local network to the mobile network merely transports data between these two elements. 